The present disclosure relates in general to high sensitivity sensors, and more specifically, to high sensitivity sensors utilizing ultra-fast laser pulse excitations and time delayed detectors combined with pupil plane integrated signal detection for signal-to-noise (SNR) enhancement.
Fluorescence detection is a technique that analyzes fluorescence from a sample. A beam of light, such as from a lamp, a laser, or a light-emitting diode (LED), excites electrons in molecules of certain compounds and causes them to fluoresce or emit light, which is typically, but not necessarily, visible light. The emitted fluorescent light reaches a detector, which can be placed at 90° to the incident light beam to minimize the risk of transmitted or reflected incident light reaching the detector. The detector can either be single-channeled, which detects intensity one wavelength at a time, or multi-channeled, which detects the intensity of all wavelengths simultaneously. At low concentrations, the fluorescence intensity will generally be proportional to the concentration of the fluorophore.
Fluorescence detection offers one of the most sensitive methods for quantification of probe molecules in biological and material systems. Consequently, this technique is widely used in the assaying of biochemical and cellular samples.